Question

find the area and perimeter of a semicircle whose diameter is 2.8cm

Answer 1

Answer: See to find anything related to semi circle we need to know about the formulas of a circle

Area of circle : πr²

Permieter : 2πr

Step-by-step explanation:

Since a semi circle is the half of a circle... The half of all these formulae will become the formulae of a semi circle

That is, Area of semi circle : πr²/2

             Perimeter                : 2πr/2  (ie) πr    

Since diameter of semi circle is 2.8cm, radius is 2.8/2=1.4cm

Area= 22/7*1.4*1.4/2

= 22*1.4*1.4/14 (since 7*2=14)

= 22*0.1*1.4 (since 1.4/14=0.1)

=3.08 cm²

Perimeter: 22/7*1.4= 22*0.2= 4.4cm

Hope u understood .......pls

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